The use of water-repellent and water-impermeable barriers in conjunction with fabrics to prevent penetration by water or water-based liquids of garments or particular sections of gaments, especially surgical gowns, has long been known. General water repellency of fabrics can be achieved by treating the fabric with waterproofing chemicals. Such water repellency treatments for surgical gown fabrics are disclosed in U.S. Pat. No. 2,668,294 issued to Gilpin on Feb. 9, 1954, U.S. Pat. No. 3,218,649 issued to Ricter on Nov. 23, 1965, U.S. Pat. No. 3,229,305 issued to Nevitt on Jan. 18, 1966, and U.S. Pat. No. 3,349,285 issued to Belkin on Oct. 24, 1967. Such water repellency treatments are generally not complete barriers to the passage of water in that a sufficient pressure can cause water to penetrate such water-repellent fabrics. A water-impermeable surgical gown can be achieved by the use of a plastic film as disclosed in Ricter.
Water-repellent fabrics provide a sufficient water barrier in most regions of a surgical gown. However, certain regions of the gown are exposed to a combination of large amounts of liquid contact and pressure applied due to contact of the wearer with the surgical table or patient. These regions, which are the central operative region of the upper gown front and the lower sleeves, are particularly susceptible to liquid penetration of the fabric (hereinafter generally referred to as "liquid strikethrough"). Where liquid strikethrough occurs, there is an increased danger of contamination and resulting infection for the patient.
Extra layers of water-repellent and water-impermeable materials have been placed on the central operative region and lower sleeves of surgical gowns in order to provide added protection against liquid strikethrough in these critical areas. References which disclose such zones of protection are U.S. Pat. No. 3,011,172 issued to Tames on Dec. 5, 1961; U.S. Pat. No. 3,359,569 issued to Rotanz, Scrivens and Hanlon on Dec. 26, 1967; U.S. Pat. No. 3,803,640 issued to Ericson on Apr. 16, 1974; U.S. Pat. No. 3,868,728 issued to Krzewinski on Mar. 4, 1975; U.S. Pat. No. 4,171,542 issued to Cox, Johnson, Maskey and Mueller on Oct. 23, 1979; and U.S. Pat. No. 4,214,320 issued to Belkin on July 29, 1980.
In recent years disposable surgical gowns have increased in usage in order to avoid laundering and sterilizing of reusable gowns. Also, the disposable gowns can be more easily treated for water-repellency and water-impermeability since they do not have to withstand repeated laundering and sterilization. However, since such disposable surgical gowns are used only once, the materials from which they are made and the processes for making them must be kept as inexpensive as possible in order to make the disposable gowns affordable.
Nonwoven fabric laminates utilizing webs of microfine hydrophobic fibers have recently come into use as fabrics which are highly water-repellent while still moderately air-porous. Examples of such webs are melt-blown webs of the type taught in the article entitled "Superfine Thermoplastic Fibers" by Van A. Wente, appearing in Industrial Engineering Chemistry, August, 1956, Vol. 48, No. 8 (pp. 1342-1346). Fabrics incorporating such webs for use as liquid barriers are disclosed in U.S. Pat. No. 3,837,995 issued to Floden on Sept. 24, 1974; U.S. Pat. No. 3,916,447 issued to Thompson on Nov. 4, 1975; and U.S. Pat. No. 4,196,245 issued to Kitson, Gilbert and Israel on Apr. 1, 1980; and in co-pending application Ser. No. 401,169 filed July 23, 1982, in the names of Sneed, Schwam and Gregory.